Temperature trends in Europe: Comparison of different data sources

0493461 - ÚFA 2019 DE eng A - Abstrakt
Krauskopf, T. - Huth, Radan
Temperature trends in Europe: Comparison of different data sources.
EMS Annual Meeting Abstracts, Vol. 15. Berlín: European Meteorological Society, 2018.
[EMS Annual Meeting: European Conference for Applied Meteorology and Climatology 2018. 03.09.2018-07.09.2018, Budapest]
Institucionální podpora: RVO:68378289
Klíčová slova: temperature trends * long-term changes * reanalysis * climate database * climate change
Obor OECD: Meteorology and atmospheric sciences
https://meetingorganizer.copernicus.org/EMS2018/EMS2018-234.pdf

Temperature trends differ markedly not only region-to-region and between seasons but also depending on the
selected datasets. Only a few studies attempted to compare temperature trends between data sources of different
types. Here, one station-based (ECA&D), two gridded (E-OBS; CRUTEM) and two reanalysis (ERA-40;
NCEP/NCAR) datasets are used for long-term temperature change detection. The period from 1957 to 2002 when
all datasets overlap is examined and the linear regression method is utilized to calculate temperature trends in each
season separately for 92 ECA&D stations, 325, 60, 323 and 212 grid points of E-OBS, CRUTEM, ERA-40 and
NCEP/NCAR, respectively. Raster maps illustrating the differences in trends between datasets across European
domain are accompanied by mean temperature series showing the causes of these discrepancies. We demonstrate
that trends in reanalyses deviate considerably from the other datasets mainly because the type and amount of data
assimilated into them change in time. Interestingly, whilst the ERA-40 shows lower trends due to an overestimation
of the mean temperature prior 1967, the NCEP/NCAR reveal lower trends compared to other datasets owing
to mean temperature underestimation at the end of the examined period. A noticeable anomaly in NCEP/NCAR
data was detected in Eastern Europe in summer with temperature trends nearly twice as steep compared to other
data sources. The study also reveals the weaknesses of the observation-based data sources, such as the unstable
number of stations entering the interpolation over time in the case of gridded data or the lack of representativeness
of selected ECA&D climate stations.
Trvalý link: http://hdl.handle.net/11104/0286828